Endodontal-periodontal lesion (E-P Lesion) often appears in advanced periodontal disease with deep pocket formation and/or severe bone resorption extending to the root apex. E-P Lesion associated with periodontal disease was mainly divided into 2 types, one is periodontal pulpal disease such as ascending pulpitis, and another is combination between periodontal pocket and endodontic apical lesions. However, there were no apparent reports concerning site and incidence of E-P Lesions. The purpose of this study were to survey the site and incidence of periodontal pulpal disease and combined endo-perio lesion. We sampled 295 teeth with periodontal destruction beyond the root apex out of 114 perbdontal patients. The patients were 51 males and 63females, aged l4 to 71.They have been periodontally treated and maintained since their first visit to our clinic. E-P Lesion was diagnosed by clinical examinations and X-ray findings. In incidence of E-PLesion, periodontal pulpal disease (ascending pulpal lesions) was 36 cases (12.2%), true combined endo-perio lesions were l7cases (5.8%), endodontic acute periodontitis were 2 cases (0.7%), possible periodontal pulpal lesions were 151 cases (51.2%), and the others were 89 cases (30.2%). The frequency of periodontal pulpal disease was high at the upper molar (21/88:23.9%) and the upper incisor (10/42:23.8%), and was lower at the canine (0%), the premolar (2/61:3.3%), and lower incisor (4.1%). On the other hand, true combined lesion was high at the lower molar (14/49:28.6%). The present investigation speculated that bone resorption to the root apex did not always mean nonvital of the pulp especially in upper premolar and lower incisor. E-P Lesion may occur in some sites, and the sites liable to occur E-P Lesion seem to be related to anatomical factors such as the apical shape of the root and to functional factors such as biting force.
